How a University of Calgary satellite is helping the effort to dodge space debris

As Earth's orbit is becoming more littered with detritus, Calgary-based scientists are working with partners in the U.S. to find a way for satellites to dodge space debris.

The University of Calgary is gathering data from CASSIOPE, a satellite it operates, and working with the University of Alaska Fairbanks to find ways to detect space debris and predict where it's going, so satellites can be moved out of its path.

Researchers are doing this by using a radio receiver onboard CASSIOPE that can detect plasma waves coming off of objects in Earth's ionosphere. The goal is to build an automated system that detects plasma waves, predicts where objects are moving, and acts as an early warning system so satellites can be moved out of the way of oncoming objects.

With around 8,000 satellites currently in low-Earth orbit, Andrew Howarth, the U of C's manager of space research projects, said space debris is a growing problem. Even small objects in orbit, such as when existing satellites break apart into pieces, can damage other satellites or space stations.

"You effectively get to the point where space can be inaccessible because of all the pieces floating around up there, moving around at 27,000 km/h. It's quite a potential problem," Howarth said.

At such high speeds, debris can have an impact equivalent to the energy of a small hand grenade, punching holes in critical systems on satellites or space stations.

While the North American Aerospace Defence Command (NORAD) tracks objects in low-Earth orbit from the ground, it can only detect objects that are 10 centimetres or larger. The project between the U of C and University of Alaska Fairbanks seeks to detect objects down to one centimetre in size, because there are more of these small objects in orbit.

"Occasionally, satellites do run into each other, or somebody uses some sort of test weapon to blow a satellite up, and now that one satellite becomes 2,000 pieces of space debris which are smaller. The smaller they get, the harder they are to detect with either a radar or optical instrument," University of Alaska Fairbanks research professor Paul Bernhardt said.

After a proof of concept in 2021 found CASSIOPE's radio receiver could detect radio waves from objects as they passed by within 10 kilometres, a project was funded by Intelligence Advanced Research Projects Activity to refine plasma-wave tracking.

The danger of space debris has already been seen in the past, such as when a small object put a five-millimetre hole through insulation covering the Canadarm on the International Space Station. Howarth said researchers want to ensure that a series of collisions don't create exponentially more objects floating in space.

"The big concern is that two satellites will collide and then that will create hundreds or thousands of pieces of debris," Howarth said.

"The debris itself will come back down to Earth and burn up in the atmosphere, but that takes months or years depending on the altitude."

CASSIOPE, or the Cascade Smallsat and Ionospheric Polar Explorer, was originally launched on an 18-month mission in 2013 to collect data on space storms. But 12 years later, it's proven to still be effective. Howarth said they expect it to remain operational, barring an electronics failure, until 2030 or 2031 when it re-enters Earth's atmosphere.

Howarth said his team is also working with the University of Alaska Fairbanks to develop a prototype spacecraft with even more complex plasma-wave tracking than CASSIOPE. Currently, the U of C device is the only satellite in low orbit  that can measure this data due to its radio receiver and the elliptical orbit it travels on, which allows it to interact with other objects at various altitudes.